The Incubation Period of Dinosaur eggs has been a subject of interest to researchers. A team of researchers led by Gregory Erickson, a Florida State University professor of biological science, found out through extensive research that dinosaur eggs typically took three to six months to incubate, depending on the dinosaur. Whether the incubation duration of dinosaurs is similar to that of the birds or the reptiles has been a matter of debate. To resolve this question, the researchers examined rare fossils of dinosaur embryos of Protoceratops, a sheep-sized dinosaur that laid small eggs, and Hypacrosaurus, a huge duck-billed dinosaur that laid eggs weighing more than four kilograms. The jaws of the embryos were studied using CT scans and microscopes since growth lines on the teeth are an indication of the incubation period. According to the researchers, “These are the lines that are laid down when any animal's teeth develops. They're kind of like tree rings, but they're put down daily.” From these records it was confirmed that the eggs hatched after three to six months. These findings can aid in understanding why dinosaurs became extinct at the end of the Cretaceous period while other reptiles, birds, and amphibians survived. Since the incubation period of the dinosaurs was long, they are likely to have been at a disadvantage, needing more time and resources to reach maturity.